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DEAR NEW FARM:
I am a Ph.D. student at the University of Florida and am taking
a class on world agriculture. The instructor is very dogmatic
about the use of synthetic nitrogen. I would appreciate any
information you might have as well as other sources you can
lead me to that I can use in this class to provide the other
side of the argument.
Thank you,
Brad Walker
DEAR BRAD:
You are probably aware that UF just cut the ribbon on the
first dedicated organic research department of any land grant
university in the U.S:
www.napa.ufl.edu/digest/stories/organic0301.html.
Someone over there might offer you some good cannon fodder,
or even better, help you to build a bridge between the mainstream
agriculture department and the folks who have got it right!
We get frustrated ourselves when we hear reporters repeat
as statement of fact that synthetic nitrogen is necessary
to feed a burgeoning population (NPR, no less) every time
they do a peice on Fritz Haber or some other related historical
figure connected to the synthesis of nitrogen.
We believe that the poor farm management practices so ubiquitous
across the American landscape are largely due to who has traditionally
funded land grant universities: the companies that make pesticides
and herbicides, synthetic fertilizers, and are now pushing
transgenic crops.
The late Donella Meadows wrote an excellent piece for the
September/October 2000 issue of Organic Gardening magazine
entitled Our
Food, Our Future which lies bare the myth of synthetic
inputs and GMOs as the only hope for feeding a burgeoning
world population. After derailing this notion, Meadows explains
why, and how, organic agriculture can do the job just fine.
The Rodale Institute’s Farming Systems Trial® and
Compost Utilization Trial have produced a number of peer-reviewed
research papers that demonstrate how nitrogen is more efficiently
utilized in an organic system. Among these findings, says
research agronomist Dave Wilson, are the facts that:
- Synthetic fertilizers make nitrogen available to crops
very quickly. This makes them more prone to leaching, which
can pollute surrounding land and water—think dead
zones in the Chesepeak Bay and Gulf of Mexico. Organic nitrogen
sources are released slowly throughout the growing season
and contribute to N reserves in the soil. Organic amendments
can also improve soil structure and stimulate soil biological
processes, particularly in degraded soils.
- Synthetic nitrogen fertilizers speed up the decay process
of organic matter so that it is released in the atmosphere
as carbon dioxide, a major greenhouse gas. In an organic
system, carbon is stored in soil and plant tissue and is
recycled.
- Leguminous cover crops, an integral part of an organic
system, fix nitrogen from the earth’s atmosphere and
accumulate soil carbohydrates through plant biomass. These
“green manures” also improve soil structure
and help prevent erosion. They go to work deep in the soil,
fostering symbiotic relationships between soil microbes
and living roots; beneficial products of these relationships
include mycorrhizal fungi, which bolster a plant’s
ability to take up nutrients and water, and glomalin, a
glue-like substance that binds soil particles together and
a contributes to tilth and stability.
For more on the subject, you can purchase the publication
The
Rodale Institute Farming Systems Trial™ in our bookstore.
Some of the Institute’s peer reviewed articles on this
subject include:
- Hu, S., Grunwald, N., Van Bruggen, A., Gamble, G.,
Drinkwater, L., Shennan, C., and M. Dement. 1997. Short
term effects of cover crop incorporation on soil carbon
pools and nitrogen availability. Soil Science Society of
America Journal 61(3):901-911.
- Pallant, E., Lansky, D., Rio, J., Jacobs, L., Schuler,
G., and W. Whimpenny. 1997. Growth of corn roots under
low-input and conventional farming systems. American Journal
of Alternative Agriculture 12(4):173-177.
- Drinkwater, L.E., Wagoner, P. and M. Sarrantonio.
1998. Legume-based cropping systems have reduced carbon
and nitrogen losses. Nature 396: 262-265.
- Douds, D., and P. Millner. 1999. Biodiversity
of Arbuscular Mycorrhizal fungi in Agroecosystems. Agriculture,
Ecosystems and Environment 74:77-93.
- Drinkwater, L., Janke, R., and L. Rossoni-Longnecker.
2000. Effect of tillage and intensity on nitrogen dynamics
and productivity in legume based grain systems. Plant and
Soil 227(2):99-113.
NF
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